<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>tab栏切换</title>
    <style>
      * {
        margin: 0;
        padding: 0;
      }

      .tab {
        width: 590px;
        height: 340px;
        margin: 20px;
        border: 1px solid #e4e4e4;
      }

      .tab-nav {
        width: 100%;
        height: 60px;
        line-height: 60px;
        display: flex;
        justify-content: space-between;
      }

      .tab-nav h3 {
        font-size: 24px;
        font-weight: normal;
        margin-left: 20px;
      }

      .tab-nav ul {
        list-style: none;
        display: flex;
        justify-content: flex-end;
      }

      .tab-nav ul li {
        margin: 0 20px;
        font-size: 14px;
      }

      .tab-nav ul li a {
        text-decoration: none;
        border-bottom: 2px solid transparent;
        color: #333;
      }

      .tab-nav ul li a.active {
        border-color: #e1251b;
        color: #e1251b;
      }

      .tab-content {
        padding: 0 16px;
      }

      .tab-content .item {
        display: none;
      }

      .tab-content .item.active {
        display: block;
      }
    </style>
  </head>

  <body>
    <div class="tab">
      <div class="tab-nav">
        <h3>每日特价</h3>
        <ul>
          <li><a class="active" href="javascript:;" data-id="0">精选</a></li>
          <li><a href="javascript:;" data-id="1">美食</a></li>
          <li><a href="javascript:;" data-id="2">百货</a></li>
          <li><a href="javascript:;" data-id="3">个护</a></li>
          <li><a href="javascript:;" data-id="4">预告</a></li>
        </ul>
      </div>
      <div class="tab-content">
        <div class="item active"><img src="./images/tab00.png" alt="" /></div>
        <div class="item"><img src="./images/tab01.png" alt="" /></div>
        <div class="item"><img src="./images/tab02.png" alt="" /></div>
        <div class="item"><img src="./images/tab03.png" alt="" /></div>
        <div class="item"><img src="./images/tab04.png" alt="" /></div>
      </div>
    </div>
    <script>
      // 获取 ul 父元素
      const ul = document.querySelector(".tab-nav ul");
      ul.addEventListener("click", function (e) {
        if (e.target.tagName === "A") {
          // 移除所有的active
          document.querySelector(".tab-nav .active").classList.remove("active");
          // 给当前的a添加active
          e.target.classList.add("active");
          // 大盒子模块
          const i = +e.target.dataset.id;
          // 移除原来的active
          document
            .querySelector(".tab-content .active")
            .classList.remove("active");
          // 给当前的item添加active
          document
            .querySelector(`.tab-content .item:nth-child(${i + 1})`)
            .classList.add("active");
        }
      });
    </script>
  </body>
</html>
